Ventilating fan with reversible pitch blade



H. c. PIHL 2,869,648

VENTILATING FAN WITH REVERSIBLE PITCH BLADE Jan. 20, 1959 Filed Aug. 9, 1956 United States Patent VENTILATING FAN WITH REVERSIBLE PITCH BLADE Hadley C. Pihl, Hinsdale, Ill., assignor to Sears, Roebuck and Co., Chicago, 111., a corporation of New York Application August 9, 1956, Serial No. 603,078

1 Claim. (Cl. 170--160.1)

My invention relates to ventilating fans and has to do more particularly with a novel construction for a fan with reversible pitch blades which is simple in construction, efficient in operation and relatively inexpensive to produce.

Broadly considered, my invention contemplates a reversible electrical motor on the rotor shaft of which is mounted a drive gear and a spider carrying diametrically opposed propeller shafts and fan blades geared to the drive shaft. Rotation of the motor in either direction will serve to rotate the drive gear and to revolve the spider along with the blades, which will also be rotated about their respective axes; reversing the motor will reverse the direction of rotation of the spider and also of the blades. Thus, the fan may be used either as a ventilator or as an exhaust fan.

My invention will be best understood by reference to the drawings attached hereto and forming a part of this specification, wherein Fig. 1 is a perspective view of a fan embodying my invention;

Fig. 2 is a fragmentary view axially of the motor, partly in section and partly in elevation, and

Fig. 3 is a transverse sectional view taken substantially along the line 3--3 of Fig. 2.

The numeral 10 represents a housing for an electrical motor of any suitable type, preferably reversible, having a shaft 15 carrying a suitable hub member 18 keyed thereto. Secured to the motor housing 10 is a bracket 20 of any suitable design for mounting the device in a window or wall opening, wherever desired.

Rotatably supported on the hub member 18 is a U- shaped spider 25 comprising a web portion 26 and opposed arms 27, 27. Fixed to the hub member 18 is a drive gear 30 which engages a pair of parallel opposed and similar spur gears 32, 32, which are fixed to a pair of alined propeller shafts 35, 35, the latter being rotatably mounted in bearings 37 carried by spider arms 27, 27. The shafts 35 carry fan blades 40, 40, of suitable design.

On the outer face of drive gear 30 is a projecting lug 45 which is engageable with a stop lug 48 projecting inwardly from the web portion 26 of spider 25 in both direc- It will be apparent that upon a reversal of rotation of the motor the gear 30 will be rotated relative to the spider 25 until the stop lugs 45 and 48 engage on their opposite sides. During such movement the spur gears 32 are caused to be rotated effecting a corresponding reversal of the blades 40 so that they are in proper position for operation of the motor in the said reverse direction.

It will thus be seen that I have provided a reversible pitch fan of extremely simple construction, having a minimum of simple parts and highly efiicient in operation.

While I have shown a spider having a single pair of opposed arms, with driven gears and fans carried thereby, additional pairs of opposed arms with blade and gear assemblies may be made a part of the spider unit actuated by the drive shaft 15.

Various changes coming within the spirit of my invention may suggest themselves to those skilled in the art. Hence, I do not wish to be limited to the specific embodiment shown and described or uses mentioned, but intend the same to be merely exemplary, the scope of my invention being limited only by the appended claim.

I claim:

In a deviceespecially suitable for use as a ventilating fan, the combination with a reversible motor having a drive shaft, of a U-shaped spider rotatably mounted on said drive shaft, said spider having a pair of opposed arm portions joined by an intermediate web portion, a propeller blade rotatably carried by each of said arm portions, each blade having a propeller shaft extending through an arm portion and a propeller gear disposed on each propeller shaft between the arm portion and motor, a drive gear fixed to said drive shaft between the motor and said web portion and drivingly engaging said propeller gears, and mutually engageable stop members disposed respectively on the outer face of the drive gear and on the inner face of said web portion, whereby the spider may be driven in reverse directions.

1,520,746 Boyce et al. Dec. 30, 1924 

